import csv

# Diviser un CSV en N fichiers de tailles équilibrées, sans ligne vide parasite
def split_csv(input_path, output_prefix, n_parts=4):
    with open(input_path, newline='', encoding='utf-8') as f:
        reader = csv.reader(f)
        header = next(reader)
        rows = [r for r in reader if r]  # ignore les lignes vides

    total = len(rows)
    print(f"Total lignes détectées : {total}")

    base = total // n_parts
    remainder = total % n_parts  # réparti sur les premiers fichiers

    start = 0
    for i in range(n_parts):
        size = base + (1 if i < remainder else 0)
        chunk = rows[start : start + size]
        start += size
        with open(f"{output_prefix}_{i+1}.csv", "w", newline='', encoding='utf-8') as out:
            writer = csv.writer(out)
            writer.writerow(header)
            writer.writerows(chunk)
        print(f"{output_prefix}_{i+1}.csv : {len(chunk)} lignes")

split_csv("mon_fichier.csv", "sortie", n_parts=4)